02-06-2017, 12:19 PM
02-06-2017, 04:23 PM
A simplistic way would be to use two circuits (or perhaps more) one to control the power of the lamps (individually or collectively according to the requirements of the studies) and one to measure the current variations in the LDR.
For the power control circuit you can simply use a rheostat or POT to control the input current of the lamps, and for the LDR you can use the following circuit
![[Image: main-qimg-35a1aadb242f660892ecfccd5f2764ba.webp]](https://qph.ec.quoracdn.net/main-qimg-35a1aadb242f660892ecfccd5f2764ba.webp)
As the power of the incandescent lamps changes, the output current will change and thus the input into the LDR, however changes may be very small and a high precision voltmeter or any other observing apparatus used may be necessary .
The above method would allow you to plot the curve between the current and potential through the LDR, you can also measure the current through it and plot the current against the current. However, these graphs will not be very accurate since the measured current is not input but output.
To find other curves such as the current frequency vs you can change the lamps with different light lamps to draw the required curves.